Commit ea673a4d authored by Steffen Klassert's avatar Steffen Klassert
Browse files

xfrm4: Reload skb header pointers after calling pskb_may_pull. 



A call to pskb_may_pull may change the pointers into the packet,
so reload the pointers after the call.

Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
parent 1a14f1e5

net/ipv4/xfrm4_policy.c

+26 −7
Original line number Diff line number Diff line
@@ -129,7 +129,10 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) 
		case IPPROTO_DCCP:

			if (xprth + 4 < skb->data ||

			    pskb_may_pull(skb, xprth + 4 - skb->data)) {

				__be16 *ports = (__be16 *)xprth;

				__be16 *ports;



				xprth = skb_network_header(skb) + iph->ihl * 4;

				ports = (__be16 *)xprth;



				fl4->fl4_sport = ports[!!reverse];

				fl4->fl4_dport = ports[!reverse];
@@ -139,7 +142,10 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) 
		case IPPROTO_ICMP:

			if (xprth + 2 < skb->data ||

			    pskb_may_pull(skb, xprth + 2 - skb->data)) {

				u8 *icmp = xprth;

				u8 *icmp;



				xprth = skb_network_header(skb) + iph->ihl * 4;

				icmp = xprth;



				fl4->fl4_icmp_type = icmp[0];

				fl4->fl4_icmp_code = icmp[1];
@@ -149,7 +155,10 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) 
		case IPPROTO_ESP:

			if (xprth + 4 < skb->data ||

			    pskb_may_pull(skb, xprth + 4 - skb->data)) {

				__be32 *ehdr = (__be32 *)xprth;

				__be32 *ehdr;



				xprth = skb_network_header(skb) + iph->ihl * 4;

				ehdr = (__be32 *)xprth;



				fl4->fl4_ipsec_spi = ehdr[0];

			}
@@ -158,7 +167,10 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) 
		case IPPROTO_AH:

			if (xprth + 8 < skb->data ||

			    pskb_may_pull(skb, xprth + 8 - skb->data)) {

				__be32 *ah_hdr = (__be32 *)xprth;

				__be32 *ah_hdr;



				xprth = skb_network_header(skb) + iph->ihl * 4;

				ah_hdr = (__be32 *)xprth;



				fl4->fl4_ipsec_spi = ah_hdr[1];

			}
@@ -167,7 +179,10 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) 
		case IPPROTO_COMP:

			if (xprth + 4 < skb->data ||

			    pskb_may_pull(skb, xprth + 4 - skb->data)) {

				__be16 *ipcomp_hdr = (__be16 *)xprth;

				__be16 *ipcomp_hdr;



				xprth = skb_network_header(skb) + iph->ihl * 4;

				ipcomp_hdr = (__be16 *)xprth;



				fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));

			}
@@ -176,8 +191,12 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) 
		case IPPROTO_GRE:

			if (xprth + 12 < skb->data ||

			    pskb_may_pull(skb, xprth + 12 - skb->data)) {

				__be16 *greflags = (__be16 *)xprth;

				__be32 *gre_hdr = (__be32 *)xprth;

				__be16 *greflags;

				__be32 *gre_hdr;



				xprth = skb_network_header(skb) + iph->ihl * 4;

				greflags = (__be16 *)xprth;

				gre_hdr = (__be32 *)xprth;



				if (greflags[0] & GRE_KEY) {

					if (greflags[0] & GRE_CSUM)

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